Revert "EDUCATOR-394 Disable self generation certificates when course is reset to instructor-paced."

This reverts commit f97f0525, reversing
changes made to 800bcd8e.

Also adds improved styling for course pacing settings, and unit tests
around query counts for self-paced courses.

ECOM-2650

ECOM-2489

fixed broken test

changes based on feedback on 6/24

fixed broken unit test after feedback changes

added more checks and updated tests

fixed broken bok choy test

Fixed pylint quality error

trying to fix pylint quality error

Filter by Language:
Designation for course language(s) in Studio
allows for filtering of courses based on their language in the sidebar
Reuses active filter view UI/IA from find courses page on edx.org
view for clearing individual or all filters, as with edx.org filtering

Clicking on conflicting option box unchecks all conflicts
LMS: Clicking license text should bring to new window
updated styles to reflect html reuse inside of xblock edit modal area.

Add ARIA attributes to license for a11y

Gracefully handle re-selecting of selected license

This allows course authors to choose between two difference licenses for their
course content: All Rights Reserved, or Creative Commons. In the backend, XBlocks
that wish to allow custom licenses need only inherit from LicenseMixin, which
adds a `license` field as a string.

License information is displayed in the Studio editor view, and just below the
rendered XBlock in the LMS. In addition, if the course block itself has a custom
license set, this license will display just below the main body of the page
on courseware pages.

This entire feature is gated behind the LICENSING feature flag.

TNL-1675

This repetitive code is especially pronounced in Stanford's fork, where
we have extended the About page to include several additional fields.

This pays down some technical debt by refactoring into a shared helper.

Refactor all callers (often replacing with more appropriate fn)

Also, added for_branch_setting method to old mongo and removed some
branch verification tests

Conflicts:
	common/lib/xmodule/xmodule/modulestore/mongo/draft.py
	common/lib/xmodule/xmodule/modulestore/split_mongo/split_draft.py
	common/lib/xmodule/xmodule/modulestore/xml_importer.py

Refactor get_parent_locations STUD-1663